Backup rolls for tinning machines



Patented Mar. 25, 1941 BACKUP ROLLS FOR TINNING MACHINES Nelson M. Jenkins, Clyde D. Michaels, Frederick Robson, and Howard C. Rodgers, Birmingham,

Ala.

Application June 5, 1940, Serial No. 339,036

4 Claims.

The present invention relates broadly to metal coatingmachines, and in particular to improved means operating in conjunction with the rolls which squeeze ofi surplus coating, for applying 1 a difierential backing-up pressure to the central and outer portions of the smoothing or squeezing rolls.

While not limited thereto, the invention is peculiarly well suited for use in connection with 10 conventional tinning machines, and for purposes of illustration we have shown such a tinning machine with modifications made thereto so as to adapt it for utilization of the invention.

For a complete disclosure of the invention, ref- 15 erence is to be made to the accompanying drawings, the following detailed description, and the appended claims.

In the drawings, Figure l is a plan view of a tinning machine 20 embodying the invention, and

Figure'2 is a cross-sectionalview on line IIII of Figure 1.

Referring in detail to the drawings, Ill represents a conventional form of tin pot adapted to 25 be heated by any suitable means, which may be conveniently located within the heating chamber I2. The metal sheet S to be coated with tin is fed in by conventional feed rolls [4 through a suitable flux contained in the usual flux box IE.

30 The rolls I 4 feed the sheet between guides Hi to feed rolls 20, guide roll 22, and fixed guide 24,

immersed in a bath of molten tin, in the usual manner. The guide 24 directs the sheet upwardly for coaction with the lowermost pair of spaced exit rolls 26 and 28. The roll 26 is mounted in a relatively fixed bearing block 30, and the roll 28 is mounted in a movable bearing block 32 positioned within the window opening 34 of a subframe 36. The bearing block 32, and conse- 40 quently the roll 28, is arranged to be urged toward the roll 26 by means of a lever 38 pivoted at 40 and having an arm 42 which at its upper end engages an eye formed in a slidably mounted rod 44 surrounded by a .;pring 46 one end of which bears against a cross-plate 48 and the other end of which engages a washer 50 whose position can be adjusted along the rod 44 by manipulation of an adjusting nut 52 screwed on the outer extremity of the rod.

- Located above the exit rolls 26 and 26 is, an-

other pair of rolls 54 and 56, the roll 56 being mounted in a relatively fixed bearing block substantially the same as the block 30 previously referred to. Likewise the roll- 54 is mounted in a 55 slidable bearing block and is arranged to be pressed toward the roll 56 by means of a rockable lever 58 engaging the eye on a rod 60 acted upon by an adjustable spring 62 in a manner quite similar to the spring mounting previously, referred to.

Located above the rolls 54 and 56 there is a pair of coacting rolls 64 and. 66, herein referred to as smoothing rolls, which are effective to squeeze off the surplus coating material and to smooth and even the finish coating. It is of utmost importance that these smoothing and finishing rolls operate with precision. When straight smoothing rolls have been used heretofore, due to deflection thereof, the coating of tin has been found to be thicker at the center of the sheet than at the edges. In order to overcome. this undesirable operating condition, tapering rolls have been used which are of a relatively large diameter at the center and smaller diameter at each end. Such tapered rolls result in the production of a more uniform coating, but they are more expensive to turn than parallel rolls and require close figuring to bring about the desired result. Moreover, unless frequent and very accurate adjustments of the rolls are made, the coating will not be of uniform. thickness from edge to edge, To overcome the difficulties which are inherent in smoothing rolls heretofore used, we provide for coaction with each of the smoothing rolls a pair of backing-up rolls arranged end to end. For example, as shown in Figure 1, backup rolls [i4 and 64" are mounted for coaction with the smoothing rolls 64. Similarly, backingup rolls 66 and 66'' are mounted in end-to-end relation for coaction with the smoothing rolls 66. The backing-up rolls 64 and 64*" are mounted at their outer ends in bearing blocks 68 and HIV respectively, and at their inner ends in similar bearing blocks 12 and 14 respectively, the latter being slidable in suitable guidways in a central- 1y located bearing bracket 16 which is secured by bolts or other fastening devices 18 to a crossmember 80 forming a part of the sub-frame 36. Suitable shims may be placed between the several bearing blocks and their supports to accurately position the backing rolls 64 and 64 The backing-up rolls 66 and 66*" are mounted at their outer ends in respective bearing blocks 82 and 84 which are normally stationary but which are adapted to be adjustably pressed toward the roll 66. The inner ends ofthe saidbacking rolls are mounted in bearing blocks 86 and 88 respectively, which are adapted to be pressed with a yielding pressure toward the smoothing roll 66. The means for applying this yielding pressure for each of the outer blocks 82 and 84 and for each of the inner blocks 88 and 88 comprises a respective lever 90 pivoted at 92 and having a toe 94 at its lower end for coaction with a respective bearing block. The upper end of each lever 90 passes through an eye portion 96 formed in the end of a rod 88 carying an adjusting nut I00 which bears against a washer I02. Interposed between each washer and the cross member 48 there is a spring I08 which, through the connections described, serves to yieldingly press the associated bearing block, and with it the end of the backing. roll, toward the smoothing roll. 66. Accordingly, there is provided in the embodiment of the invention illustrated, coacting smoothing rolls 64 and 66 which are efiective to squeeze off the surplus coating material from the sheet being coated and to even the finish coating, and a pair of backing up rolls coacting with each of the smoothing rollers, said backingup rolls being arranged end to end and being effective for applying differential backing-up pressure to the central and outer portions of the smoothing rolls. It will be understood that the differential pressure exerted between the backing-up rolls 64 and 64, with relation to the roll 64, can be secured by the insertion of suitable shims between the outer portions of the bearing blocks 68, I0, 12 and I4 and their supporting members. In the case of the backing-up rollers 66 and 66, the differential pressure can be exerted by permitting the outer bearing blocks 82 and 84 to occupy a normally fixed position of adjustment, whereupon the adjusting nuts I00 can be manipulatedto vary the pressure transmitted through the springs I06 and the levers 90 associated with the inner bearing blocks 86 and 88.

While we have described quite precisely the particular embodiment of the invention illustrated, it is to be understood that various modifications and substitutions and equivalents may be made by those skilled in the art without departure from the invention as defined ln-the appended claims.

We claim:

1. In a machine for coating metal sheets, the combination with the coacting smoothing rolls which are efi'ective to squeeze off the surplus coating material from the sheet being coated, of a backing-up roll whose outer end is journalled in a relatively fixed bearing and whose inner end terminates near the center of the length of said smoothing rolls and is journalled in a movable bearing, and means for yieldingly pressing said movable bearing toward said smoothing rolls.

2. In a machine for coating metal sheets, the combination with the coacting smoothing rolls which are efiective to squeeze oif the surplus coating material from the sheet being coated, of a pair of backing-up rolls arranged end to end for rolling coaction with one of said smoothing rolls,,and respective means for pressing the inner portion of each backing-up roll toward said one smoothing roll with a force difl'ering in magnitude from the force urging the outer portion of said backing roll toward the smoothing roll.

3. In a machine for coating metal sheets, the combination with the coacting smoothing rolls which are' effective to squeeze off the surplus coating material from the sheet being coated, of a pair of backing-up rolls arranged end to end for rolling coaction with one of said smoothing rolls, fixed bearings rotatably supporting the respective outer ends of said backing rolls, respective adjustably mounted bearings supporting the inner ends of said backing rolls, and adjustable means yieldingly urging said adjustably mounted bearings and the inner ends of said backing rolls toward the smoothing roll coacting with the latter rolls.

4. The combination with the two coacting smoothing rolls which are jointly effective to squeeze off the surplus tin from the sheet being coated, of precision means for controlling the uniformity of the coating comprising a respective tral region, whereby the thickness of the coating applied to the sheet under treatment is precisely and uniformly maintained.

NELSON M. JENKINS. FREDERICK ROBSON. CLYDE D. MICHAELS. HOWARD C, RODGERS. 

